How to Send an Invoice by Email (+ Templates)

To send an invoice by email, attach it as a PDF, write a clear subject line with the invoice number, and include a short, friendly message stating the amount, due date, and how to pay. Done well, it takes a minute and gets the invoice opened and paid. This guide covers the subject line, the message body, the right attachment format, timing, and includes copy-paste email templates you can adapt.

Create the invoice first in the invoice generator, export the PDF, then follow the steps below.

Always attach a PDF

Send the invoice as a PDF attachment, not a Word file or a pasted image. A PDF keeps its formatting on any device, looks professional, and can't be easily altered. A Word file can reflow on the client's screen (fonts shift, tables break), and a pasted screenshot is hard to file. Name the file clearly, e.g. INV-2026-014_YourBusiness.pdf, so it's easy for their finance team to save.

Write a clear subject line

The subject line decides whether the email gets opened and found later. Make it specific:

• Good: Invoice #2026-014 from Jordan Lee Design — due 18 Jul
• Weak: Invoice or Hello

Include your business name, the invoice number, and ideally the due date. Finance teams search their inbox by invoice number, so putting it in the subject helps you get paid.

Keep the message short and clear

The body should take ten seconds to read and answer three questions: what is this, how much, and how do I pay? Include:

• A one-line greeting.
• What the invoice is for and the amount.
• The due date.
• How to pay (or a note that details are on the invoice).
• A thank-you and your name.

Don't bury the details in a long message — clarity gets you paid faster.

Copy-paste email templates

Template 1 — Sending a new invoice

Subject: Invoice #2026-014 from [Your Business] — due 18 Jul

Hi [Name],

Thank you for your business. Please find attached invoice #2026-014 for [project/service], totaling $1,200, due by 18 July 2026.

You can pay by [bank transfer to the details on the invoice / the payment link]. Please reference the invoice number with your payment.

Let me know if you have any questions — happy to help.

Best, [Your Name] · [Business] · [Contact]

Template 2 — Recurring or repeat client

Subject: Invoice #2026-015 — [Month] retainer

Hi [Name],

Attached is invoice #2026-015 for [Month]'s [service], $1,500, due [date]. Same payment details as usual.

Thanks as always, [Your Name]

Send it at the right time

Timing helps:

• Send promptly — the moment the work or milestone is done, not at month-end.
• Business hours, midweek tend to get opened faster than late Friday.
• CC yourself (or send a copy) so you have a record and a timestamp.

After you send

• Log the invoice — number, client, amount, due date, status — so you can track it.
• Expect to follow up. Most late invoices just need a nudge; use a calm cadence and our unpaid invoice follow-up scripts when needed.
• Send a receipt once it's paid, if the client wants one.

A worked example: a freelancer emails invoice #2026-014 with the number in the subject line, a two-sentence body, and a clean PDF. The client's finance team files it by number and pays within the week — no back-and-forth, because everything they needed was in the email.

Related reading

• How to Write an Invoice for Freelance Work (Step-by-Step)
• How to Follow Up on an Unpaid Invoice (Email Scripts)
• How to Write Payment Terms (Net 30, Due on Receipt)

FAQ

How do I send an invoice by email? Attach the invoice as a PDF, write a clear subject line including your business name and the invoice number, and keep the message short — state what it's for, the amount, the due date, and how to pay. Send it promptly and keep a copy for your records.

What should the subject line of an invoice email say? Include your business name, the invoice number, and ideally the due date — for example "Invoice #2026-014 from [Business] — due 18 Jul." Finance teams search by invoice number, so putting it in the subject helps the invoice get found and paid.

Should I send an invoice as a PDF or Word document? Send a PDF. It keeps its formatting on any device, looks professional, and can't be easily altered. A Word file can reflow on the client's screen, and a pasted image is hard to file. Name the PDF clearly with the invoice number.

What do I write in an invoice email? A brief greeting, what the invoice is for and the amount, the due date, how to pay (or that details are on the invoice), and a thank-you with your name. Keep it to a few sentences so the key facts are easy to find.

When is the best time to send an invoice? Send it as soon as the work or milestone is complete, ideally during business hours midweek. Prompt sending gets you paid sooner, and midweek emails tend to be opened faster than those sent late on a Friday.